Juvenile salmonids undergo smoltfication at some point right before entering the ocean. That stage takes place when the fish reaches the right weight, and the right place and time. If the fish remains in the freshwater when that time comes, smoltification does not take place, resulting in a residualized fish. A residualized fish is one that becomes a resident of a freshwater system without following the typical marine lifecycle of a salmonid.
Some hatchery steelhead smolts released into a system will become residualized, due to the fact that they ate more than others in the population when being fed. Instead of sustaining a good number of hatchery adult steelhead for recreational anglers, these resident trout will negatively impact the wild salmonid population. These impacts include predation on smaller juvenile salmonids, direct competition for food and space in the river against other juvenile salmonids.
Those who fish for these trout need to be more informed on the rationalization behind the current regulations. Daily quota of four hatchery trout is there to ensure the above mentioned impacts are minimized. Most juvenile steelhead that were released into the system have most likely undergo smoltification already as the process is usually very fast.
If revision of the current regulation is needed, one should look at which of the two factors, anglers retaining possibly residualized hatchery steelhead and predation/competition of hatchery steelhead on wild steelhead, have a higher implication on the wild steelhead stock of the Chilliwack River system. To simply say the fishery should be closed because we should let them grow bigger is not the solution. There are other underlying problems that need to be looked at as well.